[Elecraft] K3 RX only in port - still confused?

[Dave G4GED]

Hi guys
I'm another prospective buyer for the K3 but a newbie to this list.

I've searched the archieves and altho' this subject has been touched on 
before, I'm afraid I'm still confused by all the options that's been 
described.

Simply put, my primary initial use for the K3 would be for 160m DXing using 
seperate RX antennas, so an RX-only i/p port is essential.

Please dont confuse me with too many fancy options. If I order the basic 
unit+ Sub rcvr, what's the  minimum accessory  I need to order to provide a 
RX-only i/p port function for the use intended above?

BTW, The sooner the K3 Manual is released, the better!

Many thanks in advance
73 Dave